# Copyright (c) 2018 Presto Labs Pte. Ltd.
# Author: leon

import logging
import json
from typing import List, Union

from tornado import gen

import coin.flow.topic_map as topic_map
from coin.base.param_util import to_list
from coin.exchange.base.ws.subscriber import WebsocketJsonSubscriberBase
from coin.exchange.huobi.ws.subscriber import TopicPatterns


def parse_method(method):
  if method.endswith('Orderbook'):
    return 'depth'
  elif method.endswith('Trades'):
    return 'trade'
  else:
    return 'Unknown'


class SubscriberBase(WebsocketJsonSubscriberBase):
  def __init__(self,
               queue,
               group_id: str,
               worker_id: str,
               symbol: Union[List[str], str],
               close_callback=None,
               logger=None):
    super().__init__(close_callback, logger or logging.getLogger(__name__))
    self._symbol = to_list(symbol)
    self._publisher = None
    self._init_publisher(queue, group_id, worker_id)

  def _init_publisher(self, queue, group_id: str, worker_id: str):
    topic_depth = topic_map.search_topic_id('%s_%s%s' %
                                            (self._topics.depth, group_id, worker_id))[0]
    topic_trade = topic_map.search_topic_id('%s_%s%s' %
                                            (self._topics.trade, group_id, worker_id))[0]

    self._publisher = {
        'depth': queue.get_writer(topic_id=topic_depth[1]),
        'trade': queue.get_writer(topic_id=topic_trade[1])
    }

    self._enable_topic_event_publisher(queue,
                                       self._topics.topic_event, [topic_depth[0], topic_trade[0]])
    self._add_teardown_callback(self._teardown_publisher)

  @gen.coroutine
  def on_open(self):
    yield self._send_subscribe_request()
    super().on_open()

  @gen.coroutine
  def _send_subscribe_request(self):
    for symbol in self._symbol:
      self._logger.debug('Subscribing %s' % symbol)
      subscribe_depth_str = json.dumps({
          "method": "subscribeOrderbook",
          "params": {
              "symbol": symbol
          },
      })
      yield self._ws.write_message(subscribe_depth_str)

      subscribe_trade_str = json.dumps({
          "method": "subscribeTrades",
          "params": {
              "symbol": symbol
          },
      })
      yield self._ws.write_message(subscribe_trade_str)

      yield gen.sleep(0.5)  # Sleep 0.5 second before next request

    self._publish_topic_event('START')
    self._logger.info('Subscribe done')

  def _teardown_publisher(self):
    if self._publisher:
      for _, publisher in self._publisher.items():
        publisher.close()
      self._publisher = None

  def on_message(self, timestamp: int, message: bytes):
    if self.stopped:
      return

    if 'method' not in message:
      self._logger.warning('Unknown message: %s' % message)
      return
    method = message['method']

    type = parse_method(method)
    try:
      self._publisher[type].write(timestamp, message)
    except (KeyError, ValueError):
      self._logger.error('Unknown channel: %s' % message)


class HitbtcSubscriber(SubscriberBase):
  def __init__(self,
               queue,
               group_id: str,
               worker_id: str,
               symbol: Union[List[str], str],
               close_callback=None,
               logger=None):
    self._topics = TopicPatterns(
        depth='hitbtc_ws_depth',
        trade='hitbtc_ws_trade',
        topic_event='hitbtc_ws_topic_event',
        delta_depth=None,
    )
    super().__init__(queue, group_id, worker_id, symbol, close_callback, logger)
    self._register_url('wss://api.hitbtc.com/api/2/ws')
